URGENT!!: Distance Measurement System Using PIC 16f877 & TS601-01 Ultrasonic Sensor

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sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;
 
sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
 
unsigned tOld, tNew;
char edge = 0;
char capture = 0;
unsigned tword;
int distance;
 
//Functions
void interrupt();
 
 
//main function
void main() {
 
  int no1,no2;
  char display[7];
  char display1[7];
  Lcd_Init();                        // Initialize LCD
  Lcd_Cmd(_LCD_CLEAR);               // Clear display
  Lcd_Cmd(_LCD_CURSOR_OFF);          // Cursor off
 
  TRISC = 0;        // assign PORTC as output
  TRISC.B2 = 1;     // RC2 must be input
  T1CON = 0x1;      // Timer1 ON, internal clock Fosc/4
  INTCON.GIE = 1;   //Enable Global Interrupts
  INTCON.PEIE =1;   //Enable Peripheral Interrupts
  PIE1.CCP1IE = 1;  // enable interrupt capture
  TRISD=0;
  PORTD=0;
  CCP1CON = 0x04;   // Capture mode every falling edge
 
  Lcd_Out(1,1,"   Measure the    ");
  Lcd_Out(2,1," distance  using  ");
  Delay_ms(1000);
  Lcd_Out(1,1,"   Ultrasonic     ");
  Lcd_Out(2,1,"     Sensor       ");
  Delay_ms(1000);
  Lcd_Cmd(_LCD_CLEAR);
  Delay_ms(500);
 
  Lcd_Out(1,1,"Distance is:");       //Display Charactors on the LCD
 
 while(1){       //Start never ending while loop
 
  if(capture){
  PIE1.CCP1IE = 0; // disable interrupt while processing
  capture = 0;     // clear flag
 
  // Calculate length of pulse from rising edge to rising edge
  tword = ~tOld + tNew+1;
  // tword contain length of pulse in micro second
  distance=tword /58.2;      // 29.1 us = 1cm
 
  Lcd_Out(2,1,distance);
 
  Lcd_Out(2,11,"c");
  Lcd_Out(2,12,"m");
  
  
   if (distance>=5) {  //MODIFIED
     PORTD = 0xf0;
     }
   else if (distance<5) { //MODIFIED
     PORTD = 0x0f;
     }
 
 
 
  PIR1.CCP1IF = 0; // clear CCP flag
  PIE1.CCP1IE = 1; // enable interrupt
 
 }
 
}// End of while
 
} // End of main
 
void interrupt() {
 
if(PIR1.CCP1IF==1){          //Check CCP1 enterrupt
 
if(!edge){
tOld = (256*CCPR1H)+CCPR1L; // keep starting value
edge = 1;
PIE1.CCP1IE = 0;            // disable interrupt for change
CCP1CON = 0x05;             // Capture mode every rising edge
PIE1.CCP1IE = 1;            // Enable interrupt capture
 
}else{
tNew = (256*CCPR1H)+CCPR1L; // Keep ending value
capture = 1;                // Complete capture, set a flag
edge = 0;
PIE1.CCP1IE = 0;           // disable interrupt for change
CCP1CON = 0x04;            // Capture mode every falling edge
PIE1.CCP1IE = 1;           // Enable interrupt capture
 
}
 
PIR1.CCP1IF = 0; //Clear CCP flag
}
}